This invention relates to a hydraulic cylinder and piston assembly, and more specifically, this invention is concerned with the securement of a piston assembly to a piston rod.
A conventional method of attaching a piston rod to a piston is by means of a piston pin. The piston pin allows the piston to maintain alignment in the cylinder bore while permitting some angular displacement of the piston rod. However, in hydraulic cylinders that are used on earthworking equipment and the like, it is conventional to pivotally mount the cylinder to a frame with the end of the piston rod being pivotally mounted to a reactive member. Thus, it is not necessary that the piston be pivotally mounted to the piston rod, and therefore, several types of attaching means have been developed for connecting the piston to its rod.
In hydraulic cylinders of the type described hereinabove, it is common to have one end of the piston rod threaded for the purpose of receiving an internally threaded piston or a nut that is tightened after the piston is located on the rod. A problem with this type of assembly is that considerable torque is necessary to assure the attachment of the piston to the piston rod, thereby requiring special tools and substantial labor. Another method of attaching a piston to a piston rod is to use a split ring and multiple part piston arrangement. The cost of this type of piston to rod assembly is high due to the necessity of extensive machining operations for the piston and piston rod seals.
Thus, it is a principal object of the present invention to provide a simple and economical piston and piston rod assembly which avoids the complex and costly attaching means that have been utilized heretofore.